Thin, highly crosslinked polymer layer synthesized via photoinitiated graft copolymerization on a self‐assembled‐monolayer‐coated gold surface

Abstract

AbstractA thin, highly crosslinked layer was grafted onto an alkyl thiol self‐assembled‐monolayer (SAM)‐coated gold surface with N,N′‐methylene bisacrylamide (MBAA), a widely used crosslinker with two polymerizable groups, as the monomer. Surface‐initiated photografting copolymerization was achieved through the immobilization of the hydrogen‐abstraction photoinitiator benzophenone on the hydrophobic alkyl surface via physical adsorption and subsequent UV irradiation in the presence of an MBAA solution. The growth of the grafted poly‐MBAA layers seemed to produce dendritic structures with low surface coverage. At a higher monomer concentration (15 g/L of water), full coverage of the gold surface with a thin layer was obtained and proved by scanning force microscopy and contact‐angle measurements. The evaluation of the gold, gold–SAM, and gold–SAM/grafted poly‐MBAA layers with a surface plasmon resonance sensor system revealed that the photografted, thin, highly crosslinked polyacrylamide layers had a very low affinity toward the adsorption of protein. Therefore, this provides a very promising approach to tailoring materials for sensors and other applications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 158–164, 2005